Construction for and method of evacuating cans



June 24, 1930.

L. W. HILLS CONSTRUCTION FOR AND METHOD OF EVACUATING CANS Filed March 20, 1928 FIE 25 ing Patented June 24,1930

; u'm'rsn STAT-ES PATENT msnrn w. HILLS, or SAN FRANCISCO, CALIFORNIA, 'ASSIGNOR TO HILLS Janos, or SAN FRANCISCO, CALIFORNIA, A CORPORATION or cnmronmn .GOIN'STRUC'I'ION FOR AND METHOD OF EVACUATTNG CAN S.

Application filed March 20, 1928. Serial No. 63,196.

This invention relates to a can construction, particularly one in which the cover is held in position on the can body so that access thereto is possible so that vapors can be removed from material in the can, or so that the vacuumization of the can is possible without danger of dislodging the cover from the can.

It is an object of the present invention to devise a novel can construction which facili tates the subsequent evacuating of the can.

It is a further "object of the invention to provide a method of evacuating a container, particularly a filled container, so that the 'evacuating operation is facilitated as is the subsequent attachment of thecontainer cover.

A still further object of the invention is to devise a method of evacuatin a container in a novel manner to the end or facilitating 2o removal of certain substances present in the container.-

The container construction and evacuating method of thy invention have been employed with particular success in the vacuum packcoflee. While Ishall preferably describe the invention in this connection it can be applied to the packing of other materials and to the formation of containers for other substances. A The invention has also proven of particular benefit when used in connection with vacuum sealin machines which seal cans in a short duration of time under a 25inch vacuum or higher. Before hermetically sealing cans containing food products, such as roasted coffee, it is desirable to remove a part of the air and preferably'substantially all of the air from the cans. This is customarily done by subjecting the filled, unsealed can to a vac- 40 while it is still in the vacuum.

Granular-products, such as ground coffee,

. contain a considerable amount of air between the particles thereof. The filled cans, usually with the unsealed ends thereon, are introduced into the vacuum double seaming machine, in which a vacuum in excess of 13 pounds per inch usually obtains, and, in modern. practice, the cans are passed rapidly liv thr ug the machine, so that t y are u uum and in then hermetically sealing the can' my inven i n.

jected to the vacuum for a very short interval of time, in some cases as short as three seconds, before the ends are double seamed thereon. The abrupt subjection ofthe can to the vacuum and the very shortinterval of evacuating action, requires that means must be providedfor'permitting the free exhaust of air from the can, in order that a properly exhausted, perfectly sealed can will result from the vacuumizing and double seaming operations without exce tion. The difference in pressure on opposite sides of the can end, when the can is introduced into the vacuum chamber, may momentarily reach a magnitude of several hundred ounds in the case of a 5 inch diameter en and the can end must be socheld in place on the can that it will not be dislodged when subjected to this pressure. At the same time, however, the can end must be so related to the can, that a full vacuum is produced in the can in the very short interval elapsing between the entry of the can into the vacuum cham-\ ber and the double seaming of the cover to the can body. These conditions I have met by providing means for holding the can end to the body and at the same time providing free air passages for the exhaust of the air from the can.- The practical results of the use of my invention are that of obtaining a full vacuum in each can going through the vacuum double seaming machine without interfering with the perfection of the double seams, allowing an i'ncrease'inthe speed of the machine.

My invention possesses other features of advantage, some of which with the fore oing, will be set forth in the following description of the preferred is illustrated in the and forming part of It is to be understood that I do, not limit myself to the showing made in the drawings and description,.as I may adopt variations of the preferred form within the scope of my invention as set forth in the claims. I

Referring to the drawings. I r

Fig. 1- is a partial bottom plan view of 'a can and can end interengaged according to drawings accompanying OFFICE the present specifications.

form of my invention which Fig. 2-is a. sectional view of the periphery of the can and its cover prior to the clinching operation the view being taken'to agree substantially with line 2-2 of Figure 1.

Fig. 3 is a sectional view of one portion of the periphery of a can and its .cover subsequent to the clinching operation .theview being taken to agree substantially with line 33 of Figure 1.

Fig. 4 is a sectionalview of the periphery of the can and its cover subsequent to the clinching operation showing a section of these members which has not been subjected to the clinching action, showing the cover in its extended position due to the action of the vacuum, and showing the free air passages between the cover and the can.

Fig. 5 is a section of the periphery of a can and its cover subsequent to the clinching v of a vacuum.

operation and showing the interengagement of the can and cover due to the, clinching operation when the cover is under the influence The invention comprises the provision of spaced contact points on the can end whichunderlie the can body flange, and which are spaced below the flange, so that when the can end is raised, as when'a vacuum is applied, these contact points engage the can ody flange, preventing dislodgment of the can end and at the same time providing free air passages between the flange and the can end at those areas which lie between the spaced contact points. The contact points are preferably formed by turning under the can end flange at spaced points, and the turned under portions are spaced away from.

the can body flange, to provide for the free longitudinal movement of the can end, in

' filled prior to the clinching action,

order to provide the free exhaust passages. v -When using cans embodying my invention for packing coffee, the cans are preflerably t e can I ends after filling being placed in position as shown in Fig. 2. The can comprises a body member 1, the mouth of which is provided with an outwardly flared end, forming the peripheral flange 2, which in practice is shaped substantially as shown in Fig. 2. The cover or can end 3 is provided with a and-may be provided with a central circular depressed area 4, although this central circular depressed area is not necessary. The flange 5 is provided with a turned: 6.- The filled cans are then over peripher passed throng a suitable clinchingmachine in which the can body flange 2 and the can 7 end flange 5 are turned down at spaced intervals, as shown in Fig. 3 and in which the periphery 6 of the can end flange is turned in toward the can body at spaced pointsso that it underlies the turned down can body flange and so that the turned in portions are spaced away from the turned down can body flange. The clinching operation may be perwith an formed by any suitable mechanism, such as a plurality of freely rotatable spaced grooved rollers over which the can is rotated. In

turning in the periphery 6 of the end flange 5, the involute 6 formed by turning in the flange straddles the downwardly bent portion of the can body flange 2. The can, with the end so interengaged, is then introduced into the vacuum chamber and the can end 3, on being abruptly subjected to the high vacuum, is forced up Figs. 4 and 5.

raised posltion there will be a plurality of definite unobstructed air passages 7 formed between the can and its can end at the spaces f between the clinched portions.

The air within the can is then free to follow the path as indicated by the arrows in Fig. 4,- thereby in a vacuum machine employing a high vacuum for. the following reasons. If the flanges 2 and 5 were not flared downwardly, the involute 6, when the'can end is under theinfluence of a vacuum,'would exert a'suf ficient pressure on the underside of the flange 2 to frequently cause the flange 2 to slip vofl the can flange. radial deformation of the upper end of the can. The involute 6' preferably has two lines of contact with the downwardly flared flange 2 thereby distributing the application to a position as shown 1n When the can end is in this This. is probably due to a I of pressure on'flange 2 although the two line contact is not essential to successful operation.

' After the exhaustion of the air from the can, the can with the end in the position shown in'Fig. 3, passes through the double sealing machine, which is arranged in the vacuum chamber, to hermetically seal the can. Prior to placing the can ends on the can body, their under, outer surfaces are coated adhesive material known to the trade as dope and indicated in the drawings as 8. The purpose of this coating of adhesive material is to insure a'perfect seal between the can end and canbody, particularlyat the point of contact of the longitudinallap seam on the can body with its can end. This material may cause the can end to adhere'to the cover, until, due to the vacuum within the chamber, there is a'certain difference of ressure on the two surfaces of the can end to orce it away from the can body.

By such an interenga'gement ofthe cans with their ends or covers, on being introduced into the vacuum chamber, the can ends are reventedfrom being blown off by thediference between the internal and external pressures to which the can is subjected, which 1 terval of time in which they remain unsealed I filled withproducts,

in the vacuum chamber. The vacuum thus obtained within the can is substantially equal to the vacuum within the vacuum chamber.

W'hile I have described the can construction in connection with the vacuum packim of coffee it is to only an-example of a successful application of the invention. Cans embodying my invention are not limited to use with cofi'ee since other substances can be placed in the can either before or after the cover has been loosely attached. Thus substances can be treated to remove certain constituents as a volatile-solvent, if desired, before the cover is sealed to the can or the cover can be left attached with only the last motion connection.

- 1. The process of can filled with products, consisting of placing a flan ed can end having a rolled periphery over t e flanged mouth of a can; in turning both the flange of the can end and the flange of the can downwardly at spaced intervals; in turning the rolled periphery of the can end under and in spaced'relation with the flange of the can at the said spaced intervals; in subjecting the filled can to a vacuum and in then the can.

2. The process of evacuating a metallic can consisting of placing a flanged can end having a rolled periphery over the flanged mouth of a can; turning the rolled periphery of the can end under and in spaced relation to the flange of the can at regularly spaced intervals, subjecting the filled can to a. vacuum and in then permanently sealing the can end to the can.

3. 'lthat step in a process of eyacuating a container which comprises placing a (mm tainer end over themouth of a container;

turnmg downwardly the periphery of both the container end and the mouth of the conand turning thedownunder in spaced relation with the periphery of the mouth of the container.

4. The process of evacuating a container be understood that this i s? evacuating a metallic tainer comprising positioning an end over the mouth of said container, turning said end downwardly about said container, and turning a portion of said end inwardly and in spaced relation to said container sothat sald end engages said container upon a relatlve movement of said end with respect to said container.

6. In combination, a peripherally flanged can body and a. can'end, said end having involute peripheral portions thereof adapted normally to engage the periphery of the can body upon a' movement of said end away from said body. I

7. In combination, a can body having a downwardly flared peripheral portion and a can end having a complementary ownwardly flared portion, the periphery of sa d end being hooked under and clinched to engage said downwardly flared bodyportion upon relative movement between said end and said body.

8. In combination a can end with a canbody, said end and said body including a lost motion connection limiting the longl tudinal movement of said end with respect to said body, said end and said body providing a free fluid passage to said body upon said longitudinal movement.

In testimony whereof, I have hereunto set my hand.

-LESLIE W. HILLS.

permanently sealing the can end. to

comprising placing an end over the mouth of said container, turning a portion of the periphery of both said end and said container mouth downwardly, turning s'aid turned portion of said end under in spaced relation to a cooperably turned portion on said mouth,

. subjecting said container :to a vacuum, and

then sealing the end to the container.

5, That step in the processing of a con- 

